[hackers] [sbase] touch: Avoid unnecessary call to stat || Michael Forney

[git]

commit 3c12b287ec819006593db1011668e1279d787459
Author:     Michael Forney <mfor...@mforney.org>
AuthorDate: Fri Jul 8 10:24:14 2016 -0700
Commit:     sin <s...@2f30.org>
CommitDate: Sat Jul 9 10:17:16 2016 +0100

    touch: Avoid unnecessary call to stat
    
    Now, we first try a utimensat. If it succeeds, we are done, if not (and no 
-c
    flag), create the file, then set the times with futimens.

diff --git a/touch.c b/touch.c
index a187241..6e63bf8 100644
--- a/touch.c
+++ b/touch.c
@@ -18,25 +18,20 @@ static struct timespec times[2] = {{.tv_nsec = UTIME_NOW}};
 static void
 touch(const char *file)
 {
-       int fd;
-       struct stat st;
+       int fd, ret;
 
-       if (stat(file, &st) < 0) {
-               if (errno != ENOENT)
-                       eprintf("stat %s:", file);
-               if (cflag)
-                       return;
-       } else {
-               if (utimensat(AT_FDCWD, file, times, 0) < 0)
-                       eprintf("utimensat %s:", file);
+       if (utimensat(AT_FDCWD, file, times, 0) == 0)
+               return;
+       if (errno != ENOENT)
+               eprintf("utimensat %s:", file);
+       if (cflag)
                return;
-       }
-
        if ((fd = open(file, O_WRONLY | O_CREAT | O_EXCL, 0666)) < 0)
                eprintf("open %s:", file);
+       ret = futimens(fd, times);
        close(fd);
-
-       touch(file);
+       if (ret < 0)
+               eprintf("futimens %s:", file);
 }
 
 static time_t